Download Ch_4 Notes - West Broward High School

Ch. 4 Notes Earth/Space
Matter
Matter: anything that takes up space and has mass.
Four states of matter:
Plasma:
 is an ionized gas
 electrons are freed from atoms or molecules.
 is a cloud of protons, neutrons and electrons
 the most common state of matter in the universe (more than 99% of our
visible universe and most of that not visible).
 examples: the sun, supernovas, flames, lightning and auroras.
Element: a substance made up of only one kind of atom. (examples: oxygen,
gold)
Atom: smallest unit of matter that cannot be broken down and still be the same
element
Atomic Structure: atoms are made of three particles:
Particle
1. Proton
2. Neutron
3. Electron
charge
found where in the atom
positive +
no charge (neutral)
negative -
nucleus (the center of the atom)
nucleus
outside of nucleus
For every proton there is one electron, making atoms neutral (no electrical
charge).
Electrons are arranged in circles (shells) around nucleus;
If an atom’s nucleus were the size of a gumdrop, the atom would be the size of
a football stadium.
Atomic Number
Written above the element = number of protons in the nucleus (is the same as
the number of electrons).
Elements differ from other elements by the number of protons and are ordered
according to their atomic number in the periodic table.
(Drawings of atoms)
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Elements usually occur in combination with other elements. Substances joined
by chemical bonds are either compounds (must be different elements) or
molecules (can be all the same or different elements).
Chemical formulas
Shows the arrangement of the elements when two or more atoms bond
together.
Example: C6H12O6 (sugar) = 6 carbon atoms, 12 hydrogen atoms, 6 oxygen
atoms
Elements and compounds often combine through chemical reactions to form
new compounds. The forces that hold together the atoms in molecules are
called chemical bonds
See Example p.94
Water Facts and Properties
Almost 70% of the human body is water.
At sea level, water boils at 100° C and freezes at 0° C.
Water Properties make life on Earth possible
1. Cohesion = water is attracted to water; forms films and drops.
Example: water drops on a waxed car, water forms a surface that
insects can walk on; water “bulges” over top of container
2. Adhesion = water is attracted to other substances, cause them to get
wet.
Examples: water moving up a plant’s stem against gravity; Water in a
glass forms a concave shape inside a container
3. High Specific Heat= water resists temperature change
4. High Heat of Vaporization
5. Water is less dense as a solid (ice has more air between molecules)
6. Universal solvent = Water dissolves many things
Chemistry of Cells
ORGANIC COMPOUNDS: contain carbon
Carbon can form many kinds of compounds, which are called organic
molecules or macromolecules (large molecules).
Polymer: a large molecule that consists of many smaller pieces called
monomers
Monomer: one part of a polymer
Organic compounds include: carbohydrates, lipids, proteins, nucleic acids
(those are macromolecules) and ATP (a small molecule)
Carbohydrates: compounds composed of carbon, hydrogen, and oxygen
(CHO)
For example glucose: C6H12O6 – 6:12:6 = 1:2:1 ratio
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Another term for carbohydrates is saccharides or sugars.
a. Monosaccharides (Mono = one); single molecules.
Examples: glucose, fructose
b. Disaccharides (Di = two); contain 2 molecules.
Examples: glucose + fructose = sucrose (table sugar)
c. Polysaccharides (Poly = three or more)
Examples:
starches (carbohydrate storage in plants),
glycogen (carbohydrate storage in animals),
cellulose (cell walls of plants),
chitin (exoskeletons of arthropods,
crustaceans)
Function: immediate source of energy.
Food examples: pasta, bread, fruit, and vegetables. The cellulose in
vegetables and fruit provides fiber.
Lipids: compounds composed of carbon, hydrogen, oxygen, and some
have phosphorus (CHOP)
Lipids include fats, oils, waxes and steroids and phospholipids (in cell
walls)
They do not dissolve in water.
Functions: for energy storage, insulation and protection.
Types of fats:
a. Saturated fats (animal fats): single bonds between atoms, harder to
break. Examples: butter, lard, fat on meat.
b. Unsaturated fats (plant fats): have double or triple bonds; easier to
break, have fewer hydrogen atoms. Examples: olive, corn, canola
oils.
Structure: Glycerol backbone, 3 fatty acids
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Proteins: compounds composed of carbon, hydrogen, oxygen, nitrogen
and sometimes sulfur (CHONS).
Function: repair our bodies.
Examples: meat, fish, eggs, beans (plant foods have less protein than foods
that come from animals)
Proteins are made of smaller pieces called amino acids. There are 20
different amino acids.
Structures made of protein: muscles (movement), all enzymes, hormones
(control and regulate many body functions), hemoglobin (transport
oxygen in the blood), antibodies (protect from disease), egg white, hair,
and feathers
Nucleic Acids: molecules composed of carbon, hydrogen, oxygen,
nitrogen and phosphorus (CHONP). Nucleic acids are made of subunits
called nucleotides.
Function: Heredity or Code for Protein
Nucleotides have three parts:
1. Five-carbon sugar
2. Nitrogen-containing base
3. Phosphate group
There are two kinds of nucleic acids:
DNA (deoxyribonucleic acid) - two strands
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RNA (ribonucleic acid) - one strand
ATP:
Single nucleotide with two extra energy-storing phosphate groups
Used for temporary storage of energy. Not a macromolecule.
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